Improving catalogue matching by supplementing astrometry with additional photometric information
Autor: | Tom J. Wilson, Tim Naylor |
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Rok vydání: | 2017 |
Předmět: |
Data products
FOS: Physical sciences Library science 02 engineering and technology Astronomical survey 01 natural sciences Infrared Processing and Analysis Center law.invention Methods statistical law 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics Newtonian telescope Astrophysics::Instrumentation and Methods for Astrophysics Astronomy 020207 software engineering Astronomy and Astrophysics Astrometry Astrophysics - Astrophysics of Galaxies Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics - Instrumentation and Methods for Astrophysics |
Zdroj: | Monthly Notices of the Royal Astronomical Society. 473:5570-5590 |
ISSN: | 1365-2966 0035-8711 |
DOI: | 10.1093/mnras/stx2692 |
Popis: | The matching of sources between photometric catalogues can lead to cases where objects of differing brightness are incorrectly assumed to be detections of the same source. The rejection of unphysical matches can be achieved through the inclusion of information about the sources' magnitudes. The method described here uses the additional photometric information from both catalogues in the process of accepting or rejecting counterparts, providing approximately a factor 10 improvement in Bayes' factor with its inclusion. When folding in the photometric information we avoid using prior astrophysical knowledge. Additionally, the method allows for the possibility of no counterparts to sources as well as the possibility that sources overlap multiple potential counterparts. We formally describe the probability of two sources being the same astrometric object, allowing systematic effects of astrometric perturbation (by, e.g., contaminant objects) to be accounted for. We apply the method to two cases. First, we test IPHAS-Gaia matches to compare the resulting matches in two catalogues of similar wavelength coverage but differing dynamical ranges. Second, we apply the method to matches between IPHAS and 2MASS and show that the method holds when considering two catalogues with approximately equal astrometric precision. We discuss the importance of including the magnitude information in each case. Additionally, we discuss extending the method to multiple catalogue matches through an iterative matching process. The method allows for the selection of high-quality matches by providing an overall probability for each pairing, giving the flexibility to choose stars known to be good matches. 19 pages, 8 figures, 3 tables; accepted for publication in MNRAS. Updated equations 26 and 27 to fix minor typographical errors |
Databáze: | OpenAIRE |
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